A conventional illumination apparatus for sensing a human body senses a human body using an infrared sensor, an ultrasonic sensor or Doppler sensor, and controls the on and off state of illumination (Patent Documents 4 and 5), but cannot sense a danger situation of a human body.
Patent Document 1 discloses a system having a radio wave sensor for emitting radio waves and for receiving reflected waves thereof, a detector for detecting the phase and amplitude of signals received by the radio wave sensor to obtain detection signals, and a signal processor for measuring the current position, movement, respiratory rate, and heart rate of an animal or resident from the detection signal to determine the presence of an animal or resident, the system being used as resident monitoring system that can be readily installed in residences to be monitored having a variety of floor plans, and that is capable of readily ascertaining the behavior dynamics of residents and changes in the living space.
Patent Document 2 discloses a non-contact cardiopulmonary function monitoring device provided with a radio wave sensor for detecting the movements of a monitored object using the Doppler effect, wherein movement signals are passed through a respiratory rate filter in which the frequency band of a respiratory rate is used as a pass frequency band, and are passed through a heart rate filter in which the frequency band of a heart rate is used as a pass frequency band, and the respiratory rate and heart rate are calculated from the maximum amplitude in each pass frequency band.
Furthermore, Patent Document 3 discloses a monitoring system for transmitting and receiving radio waves in a residence, extracting a respiration signal in a frequency band corresponding to the respiration of a resident and a movement signal in a higher frequency band than the respiration signal, from a signal that corresponds to a reflected wave received by a radio wave sensor, and determining that the resident is in an abnormal state when the resident has not moved for a fixed length of time or longer, on the basis of the movement signal, while the respiratory signal is detected (claim 1). Also, the radio wave sensor is a Doppler sensor (claim 3).
Patent Document 1: Japanese Laid-open Patent Application No. 2010-66877
Patent Document 2: Japanese Patent No. 3057438
Patent Document 3: Japanese Laid-open Patent Application No. 2006-285795
Patent Document 4: Japanese Laid-open Patent Application No. 2011-34938
Patent Document 5: Japanese Laid-open Patent Application No. 2003-132704